Accelerated Corrosion Testing of Coatings on Metallic and other Materials
Salt Spray Tester – Salt Spray Cabinet - Chamber – Fog Apparatus is popular because it is relatively inexpensive, quick, well standardized, and reasonably repeatable. Although there may be a weak correlation between the duration in salt spray test and the expected life of a coating in certain coatings such as hot-dip galvanized steel, this test has gained worldwide popularity due to low cost and quick results.
Most Salt Spray Testers and Chambers - Cabinets today are being used not to predict the corrosion resistance of a coating, but to maintain coating processes such as pre-treatment and painting, electroplating, galvanizing, and the like, on a comparative basis. For example, pre-treated + painted components must pass 96 hours Neutral Salt Spray, to be accepted for production.
Failure to meet this requirement implies instability in the chemical process of the pre-treatment, or the paint quality, which must be addressed immediately so that the upcoming batches are of the desired quality. The longer the accelerated corrosion test, the longer the process remains out of control, and larger is the loss in the form of non-conforming batches.
The principal application of the salt spray tester is, therefore, enabling quick comparisons to be made between actual and expected corrosion resistance. Most commonly, the time taken for oxides to appear on the samples under test is compared to expectations, to determine whether the test is passed or failed.
For this reason, the salt spray tester is most often used in a quality control role, where, for example, it can be used to check the effectiveness of a production process, such as the surface coating of a metallic part.
The salt spray tester has little application in predicting how materials or surface coatings will resist corrosion in the real world, because it does not create, replicate or accelerate real-world corrosive conditions. Cyclic corrosion testing is better suited to this and you can check Qualitest’s Cyclic Corrosion Test Cabinet range for such requirements.
 QSST-270L |  QSST-480L |  QSST-800L |
Standards:
- ISO 4611 Plastics Determination of the effects of exposure to damp heat, water spray and salt mist
- ISO 7253 Paints and varnishes -- Determination of resistance to neutral salt spray (fog)
- ISO 9227 Corrosion tests in artificial atmospheres -- Salt spray tests
- ASTM B 117 Standard Practice for Operating Salt Spray (Fog) Apparatus
- ASTM B368 Standard Test Method for Copper-Accelerated Acetic Acid-Salt Spray (Fog) Testing (CASS Test)
- ASTM B 380 Standard Test Method for Corrosion Testing of Decorative Electrodeposited Coatings by the Corrodkote Procedure
- ASTM G85 - 11 Standard Practice for Modified Salt Spray (Fog) Testing
- ASTM D 1735 Standard Practice for Testing Water Resistance of Coatings Using Water Fog Apparatus
- DIN 50021 Salt Spray Testing
